Hydration affects the physical and mechanical properties of baleen tissue.
R Soc Open Sci
; 3(10): 160591, 2016 Oct.
Article
em En
| MEDLINE
| ID: mdl-27853579
ABSTRACT
Baleen, an anisotropic oral filtering tissue found only in the mouth of mysticete whales and made solely of alpha-keratin, exhibits markedly differing physical and mechanical properties between dried or (as in life) hydrated states. On average baleen is 32.35% water by weight in North Atlantic right whales (Eubalaena glacialis) and 34.37% in bowhead whales (Balaena mysticetus). Baleen's wettability measured by water droplet contact angles shows that dried baleen is hydrophobic whereas hydrated baleen is highly hydrophilic. Three-point flexural bending tests of mechanical strength reveal that baleen is strong yet ductile. Dried baleen is brittle and shatters at about 20-30â
Nâ
mm-2 but hydrated baleen is less stiff; it bends with little force and absorbed water is squeezed out when force is applied. Maximum recorded stress was 4× higher in dried (mean 14.29â
Nâ
mm-2) versus hydrated (mean 3.69â
Nâ
mm-2) baleen, and the flexural stiffness was >10× higher in dried (mean 633Nâ
mm-2) versus hydrated (mean 58â
Nâ
mm-2) baleen. In addition to documenting hydration's powerful effects on baleen, this study indicates that baleen is far more pliant and malleable than commonly supposed, with implications for studies of baleen's structure and function as well as its susceptibility to oil or other hydrophobic pollutants.
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Bases de dados:
MEDLINE
Idioma:
En
Revista:
R Soc Open Sci
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Estados Unidos